A grandfather who was convicted with child abuse after forcing his three grandsons on a hike through the Grand Canyon has been sentenced to 27 months in prison, the minimum punishment possible.

Prosecutors said Christopher Carlson, 45, of Indianapolis refused to give food and water to his three grandsons, Kevin, 12, Micah, 9, and Kameron, 8, during two separate hikes in August 2011.

In February, a jury found Carlson guilty on three of the six child abuse charges he faced.

In granting a light sentence, U.S. District Judge Frederick Martone noted that Carlson appeared to love his grandkids and has struggled with attention-deficit disorder and hyperactivity, The Associated Press reported. He could have sentenced Carlson to 17 years in jail.

Court documents obtained by the Phoenix New Times revealed more specific details and testimony from the boys about the abuse they suffered from Carlson.

After Carlson and the kids made a 7.5-mile trail on Aug. 15, park rangers confronted Carlson about complaints from other hikers that had seen the boys along the trail earlier that day. Carlson was spotted with the boys again on Aug. 28, but this time park rangers separated the boys from Carlson and asked them what happened.

According to ABC affiliate WRTV in Indianapolis, the boys told investigators that Carlson hit, choked, pinched, whipped, pushed and squeezed them constantly throughout their cross country trip that was supposed to end at Disneyland. The boys also said they were told to lie to anyone, including park rangers, about what Carlson had done to them.

The boys were later interviewed and more disturbing and specific accusations came forward about the treatment their grandfather had subjected them to.

The interviews revealed that Carlson had forced them to drink water from the Colorado River, which caused the boys to throw up multiple times, as well as kicked them repeatedly with steel-toed boots and threw them into cactuses.

Carlson told the investigators that he was trying to toughen up the boys. He was taken into custody after National Park employees said he forced the boys to go on a hike in temperatures that exceeded 100 degrees. A man died from dehydration earlier that same day on a nearby trail close to where Carlson and the boys were hiking.

During the trial, Micah testified that the worst part of the trip was throwing up and excruciating pain from the blisters on the bottom of his feet.

The blisters on the bottom of Micah's feet were so bad by the end of the second hike that they had turned into ulcers. He had to undergo treatment that is usually used for burn victims, prosecutors said.

On Wednesday, Carlson's daughter, Tara Danaher, the boys' mother, said on her father's behalf, "My father disciplined my children. In this particular case, yes, I believe he disciplined them, but I don't think he abused them."

Danaher said one of her children wrote a letter asking the judge overseeing the case to give Carlson a reduced sentence.

The letter read, "Dear judge, I would like Papa to be in jail for only one more month, it would be nice if you could let that happen."

Danaher said she thought that her father, who has been behind bars since last August, needed to see a therapist, but didn't need to be imprisoned any longer.

"At the end of the day, no matter what happened out there, I had no part of it. I didn't do anything. I didn't encourage any of it, and me and my children are being forced to suffer consequences for something we didn't do," she said.

Danaher, who is only allowed to see her children for seven supervised hours a week, said the Indiana Department of Child Services is to blame for needlessly keeping her from her children.

"My children are lost in this. They don't understand what's going on or what's taking place," Danaher said.